#totop,#totop2{

           position: fixed;right: 0;bottom: 0;

           width: 149px;height: 249px;overflow: hidden;

           cursor: pointer;display: none;

           background: url(../images/up.png) no-repeat 0px 0;

           z-index: 9999;

           }

 #totop2{
           background: url(../images/up.png) no-repeat -149px 0;
		   }